A security device can be secured to a pedal vehicle to prevent the vehicle being pedalled. The security device includes a receiving means and a securing means. The receiving means may include a through-hole means for receiving part of a frame and a pedal crank arm of the vehicle and may have an open configuration in which the frame part and a part of the crank can be placed in the through-hole means, and a closed configuration in which a frame part and crank arm are held in the through-hole means against relative movement therebetween.